November 6, 2013

Wild Blueberries Curb Risk Of Metabolic Syndrome

A bowl full of wild blueberries is not only a delicious treat, it can also protect the body against a whole host of metabolic problems if eaten daily, according to a new report in the journal Applied Physiology, Nutrition, and Metabolism. The study focused on how a long-term wild blueberry diet may help improve or prevent issues related to a condition dubbed metabolic syndrome.

"The metabolic syndrome (MetS) is a group of risk factors characterized by obesity, hypertension, inflammation, dyslipidemia, glucose intolerance and insulin resistance, and endothelial dysfunction," explains study author Dorothy Klimis-Zacas, a professor of clinical nutrition at the University of Maine. "MetS affects an estimated 37% of adults in the US.”

Wild blueberries are a rich source of polyphenols, which have been shown to provide a range of health benefits. Polyphenols, as well as other substances found in food, have the potential to prevent MetS and reduce the need for medication and medical interventions to treat metabolic ailments.

"We have previously documented the cardiovascular benefits of a polyphenol-rich wild blueberry in a rat model with impaired vascular health and high blood pressure," Klimis-Zacas said. "Our new findings show that these benefits extend to the obese Zucker rat, a widely used model resembling human MetS."

"Endothelial dysfunction is a landmark characteristic of MetS, and the obese Zucker rat, an excellent model to study the MetS, is characterized by vascular dysfunction,” she added. “The vascular wall of these animals shows an impaired response to vasorelaxation or vasoconstriction which affects blood flow and blood pressure regulation."

Study researchers found that the human equivalent of 2 cups of wild blueberries per day for 8 weeks could regulate and advance the equilibrium between relaxing and constricting factors in blood vessel walls, improving blood flow and pressure in obese Zucker rats with MetS.

She added that the study shows even greater potential since "by normalizing oxidative, inflammatory response and endothelial function, regular long-term wild blueberry diets may also help improve pathologies associated with the MetS."

Another recently published study showed that baking and cooking blueberries actually reduces the polyphenol levels of blueberries. The study team said they set out to test the stability of the beneficial compounds during cooking, proofing and baking - three processes applied to blueberry muffins or pies.

The team discovered that all three processes had mixed effects on blueberries' polyphenols – with many dropping, some staying the same and others increasing. The team theorized that the retention of polyphenols seen in their study might be the result of yeast action, which could act as a stabilizing agent during baking.

"Due to their possible health benefits, a better understanding of the impact of processing is important to maximize the retention of these phytochemicals in berry-containing-products," the researchers wrote.

From tomatoes to broccoli, blueberries are one of the many types of produce can have their health benefits negatively affected by cooking.